Energy-delivery devices with flexible fluid-cooled shaft, inflow / outflow junctions suitable for use with same, and systems including same

ABSTRACT

An energy-delivery device suitable for delivery of energy to tissue includes an antenna assembly, a chamber defined about the antenna assembly, and a cable having a proximal end suitable for connection to an electrosurgical energy source. The energy-delivery device also includes a flexible, fluid-cooled shaft coupled in fluid communication with the chamber. The flexible, fluid-cooled shaft is configured to contain a length of the cable therein and adapted to remove heat along the length of the cable during delivery of energy to the antenna assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application claiming the benefit ofand priority to U.S. application Ser. No. 12/985,136, filed on Jan. 5,2011, the entire contents of which being incorporated by referenceherein.

BACKGROUND 1. Technical Field

The present disclosure relates to electrosurgical devices suitable foruse in tissue ablation applications and, more particularly, toenergy-delivery devices with a flexible, fluid-cooled shaft,inflow/outflow junctions suitable for use with the same, and systemsincluding the same.

2. Discussion of Related Art

Treatment of certain diseases requires the destruction of malignanttissue growths, e.g., tumors. Electromagnetic radiation can be used toheat and destroy tumor cells. Treatment may involve inserting ablationprobes into tissues where cancerous tumors have been identified. Oncethe probes are positioned, electromagnetic energy is passed through theprobes into surrounding tissue.

In the treatment of diseases such as cancer, certain types of tumorcells have been found to denature at elevated temperatures that areslightly lower than temperatures normally injurious to healthy cells.Known treatment methods, such as hyperthermia therapy, heat diseasedcells to temperatures above 41° C. while maintaining adjacent healthycells below the temperature at which irreversible cell destructionoccurs. These methods involve applying electromagnetic radiation toheat, ablate and/or coagulate tissue. Microwave energy is sometimesutilized to perform these methods. Other procedures utilizingelectromagnetic radiation to heat tissue also include coagulation,cutting and/or ablation of tissue.

Electrosurgical devices utilizing electromagnetic radiation have beendeveloped for a variety of uses and applications. A number of devicesare available that can be used to provide high bursts of energy forshort periods of time to achieve cutting and coagulative effects onvarious tissues. There are a number of different types of apparatus thatcan be used to perform ablation procedures. Typically, microwaveapparatus for use in ablation procedures include a microwave generatorthat functions as an energy source, and a microwave surgical instrument(e.g., microwave ablation probe) having an antenna assembly fordirecting energy to the target tissue. The microwave generator andsurgical instrument are typically operatively coupled by a cableassembly having a plurality of conductors for transmitting microwaveenergy from the generator to the instrument, and for communicatingcontrol, feedback and identification signals between the instrument andthe generator.

There are several types of microwave probes in use, e.g., monopole,dipole and helical, which may be used in tissue ablation applications.In monopole and dipole antenna assemblies, microwave energy generallyradiates perpendicularly away from the axis of the conductor. Monopoleantenna assemblies typically include a single, elongated conductor. Atypical dipole antenna assembly includes two elongated conductors thatare linearly-aligned and positioned end-to-end relative to one anotherwith an electrical insulator placed therebetween. Helical antennaassemblies include helically-shaped conductor configurations of variousdimensions, e.g., diameter and length. The main modes of operation of ahelical antenna assembly are normal mode (broadside), in which the fieldradiated by the helix is maximum in a perpendicular plane to the helixaxis, and axial mode (end fire), in which maximum radiation is along thehelix axis.

The particular type of tissue ablation procedure may dictate aparticular ablation volume in order to achieve a desired surgicaloutcome. Ablation volume is correlated with antenna design, antennaperformance, antenna impedance, ablation time and wattage, and tissuecharacteristics, e.g., tissue impedance.

Fluid-cooled or dielectrically-buffered microwave devices may be used inablation procedures. Cooling the ablation probe may enhance the overallheating pattern of the antenna, prevent damage to the antenna andprevent harm to the clinician or patient. Because of the smalltemperature difference between the temperature required for denaturingmalignant cells and the temperature normally injurious to healthy cells,a known heating pattern and precise temperature control is needed tolead to more predictable temperature distribution to eradicate the tumorcells while minimizing the damage to surrounding normal tissue.

During certain procedures, it can be difficult for the surgeon to deployan ablation probe, e.g., between closely spaced boundaries of tissuestructures, to reach the location of the ablation site. Currentlyavailable microwave ablation devices may not be suitable for use duringopen surgical procedures when the surgeon is trying to ablate a lesionthat is not easily accessed via a midline incision. A cable assemblyconnecting the ablation probe to a generator may come into contact witha patient and may facilitate potentially unwanted heat transfer.

SUMMARY

The present disclosure relates to an energy-delivery device suitable fordelivery of energy to tissue including an antenna assembly, a chamberdefined about the antenna assembly, and a cable assembly having aproximal end suitable for connection to an electrosurgical energysource. The energy-delivery device also includes a flexible,fluid-cooled shaft coupled in fluid communication with the chamber. Theflexible, fluid-cooled shaft is configured to contain a length of thecable assembly therein and adapted to remove heat along the length ofthe cable assembly during delivery of energy to the antenna assembly.

The present disclosure also relates to an ablation device including afeedline and an antenna assembly. The feedline includes an innerconductor having a distal end, an outer conductor coaxially disposedaround the inner conductor and having a distal end, and a dielectricmaterial disposed therebetween. The antenna assembly includes anelectrically-conductive proximal arm having a proximal end and a distalend, and an electrically-conductive distal arm including a proximalportion having an outer diameter and a distal portion having an outerdiameter less than the outer diameter of the proximal portion. Theproximal end of the proximal arm is electrically coupled to andcoaxially disposed about the distal end of the outer conductor. Theantenna assembly also includes a junction member. The proximal arm andthe distal arm align at the junction member and are spaced apart alength by the junction member, thereby defining a feed gap therebetween.

The present disclosure also relates to a system including anelectrosurgical energy source and an ablation device operably associatedwith the electrosurgical energy source. The ablation device includes afeedline and an antenna assembly operatively coupled to the feedline.The feedline includes an inner conductor having a distal end, an outerconductor coaxially disposed around the inner conductor and having adistal end, and a dielectric material disposed therebetween. The antennaassembly includes an electrically-conductive proximal arm having aproximal end and a distal end, and an electrically-conductive distal armincluding a proximal portion having an outer diameter and a distalportion having an outer diameter less than the outer diameter of theproximal portion. The proximal end of the proximal arm is electricallycoupled to and coaxially disposed about the distal end of the outerconductor. The proximal arm defines a first cavity therein extendingfrom the distal end of the outer conductor to the distal end of theproximal arm. The proximal portion of the distal arm defines a secondcavity therein. The antenna assembly also includes a junction member atleast partially disposed in the first and second cavities. The proximalarm and the distal arm align at the junction member and are spaced aparta length by the junction member, thereby defining a feed gaptherebetween.

The present disclosure also relates to an inflow/outflow junctionsuitable for connection to a first tubular member disposed around atransmission line and defining a fluid inflow conduit therebetween and asecond tubular member disposed around the first tubular member anddefining a fluid outflow conduit therebetween. The inflow/outflowjunction includes a housing adapted to be coupled in fluid communicationwith a coolant supply system. The housing includes an outer wall and aninner wall cooperatively defining a fluid inlet chamber and a fluidoutlet chamber. The inner wall is configured to define an opening in thefluid inlet chamber to allow the fluid inlet chamber to be connectablein fluid communication with the fluid inflow conduit. The outer wall isconfigured to define an opening in the fluid outlet chamber to allow thefluid outlet chamber to be connectable in fluid communication with thefluid outflow conduit.

The present disclosure also relates to a system including anelectrosurgical energy source and an energy-delivery device operablyassociated with the electrosurgical energy source. The energy-deliverydevice includes an end-cap assembly defining a chamber therein, anantenna assembly disposed in the chamber; and a cable assemblyconfigured to deliver energy from the electrosurgical energy source tothe antenna assembly. The system also includes a flexible,extendable/retractable fluid-cooled shaft coupled in fluid communicationwith the chamber, wherein the flexible, extendable/retractablefluid-cooled shaft is configured to contain a length of the cableassembly therein and adapted to remove heat along the length of thecable assembly during delivery of energy to the antenna assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects and features of the presently disclosed energy-delivery deviceswith a flexible, fluid-cooled shaft and systems including the same willbecome apparent to those of ordinary skill in the art when descriptionsof various embodiments thereof are read with reference to theaccompanying drawings, of which:

FIG. 1 is a schematic diagram of an electrosurgical system including anenergy-delivery device with a flexible, fluid-cooled shaft in accordancewith an embodiment of the present disclosure;

FIG. 2A is an enlarged, cross-sectional view of the indicated area ofdetail of FIG. 1 showing a portion of a flexible, fluid-cooled shaft andan inflow/outflow junction adapted to be coupled in fluid communicationtherewith in accordance with an embodiment of the present disclosure;

FIG. 2B is an enlarged, cross-sectional view of another embodiment of aninflow/outflow junction adapted to be coupled in fluid communication theflexible, fluid-cooled shaft of FIG. 1 in accordance with the presentdisclosure;

FIG. 2C is an enlarged, cross-sectional view of yet another embodimentof an inflow/outflow junction adapted to be coupled in fluidcommunication the flexible, fluid-cooled shaft of FIG. 1 in accordancewith the present disclosure;

FIG. 3 is an enlarged, cross-sectional view of the indicated area ofdetail of FIG. 1 showing a portion of a flexible, fluid-cooled shaft andan energy-delivery device adapted to be coupled in fluid communicationtherewith in accordance with an embodiment of the present disclosure;

FIG. 4 is a cross-sectional view of a portion of a flexible,extendable/retractable fluid-cooled shaft and an inflow/outflow junctionadapted to be coupled in fluid communication therewith in accordancewith an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of the flexible, extendable/retractablefluid-cooled shaft and the inflow/outflow junction of FIG. 4 shown in aretracted configuration in accordance with an embodiment of the presentdisclosure; and

FIG. 6 is a schematic diagram of the flexible, extendable/retractable,fluid-cooled shaft and the inflow/outflow junction of FIG. 4 shown in anextended configuration in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments of energy-delivery devices with a flexible,fluid-cooled shaft and systems including the same of the presentdisclosure are described with reference to the accompanying drawingsLike reference numerals may refer to similar or identical elementsthroughout the description of the figures. As shown in the drawings andas used in this description, and as is traditional when referring torelative positioning on an object, the term “proximal” refers to thatportion of the apparatus, or component thereof, closer to the user andthe term “distal” refers to that portion of the apparatus, or componentthereof, farther from the user.

This description may use the phrases “in an embodiment,” “inembodiments,” “in some embodiments,” or “in other embodiments,” whichmay each refer to one or more of the same or different embodiments inaccordance with the present disclosure. For the purposes of thisdescription, a phrase in the form “A/B” means A or B. For the purposesof the description, a phrase in the form “A and/or B” means “(A), (B),or (A and B)”. For the purposes of this description, a phrase in theform “at least one of A, B, or C” means “(A), (B), (C), (A and B), (Aand C), (B and C), or (A, B and C)”.

Electromagnetic energy is generally classified by increasing energy ordecreasing wavelength into radio waves, microwaves, infrared, visiblelight, ultraviolet, X-rays and gamma-rays. As it is used in thisdescription, “microwave” generally refers to electromagnetic waves inthe frequency range of 300 megahertz (MHz) (3×10⁸ cycles/second) to 300gigahertz (GHz) (3×10¹¹ cycles/second). As it is used in thisdescription, “ablation procedure” generally refers to any ablationprocedure, such as, for example, microwave ablation, radiofrequency (RF)ablation, or microwave or RF ablation-assisted resection.

As it is used in this description, “energy applicator” generally refersto any device that can be used to transfer energy from a powergenerating source, such as a microwave or RF electrosurgical generator,to tissue. For the purposes herein, the term “energy applicator” isinterchangeable with the term “energy-delivery device”. As it is used inthis description, “transmission line” generally refers to anytransmission medium that can be used for the propagation of signals fromone point to another. As it is used in this description, “fluid”generally refers to a liquid, a gas or both.

As it is used in this description, “length” may refer to electricallength or physical length. In general, electrical length is anexpression of the length of a transmission medium in terms of thewavelength of a signal propagating within the medium. Electrical lengthis normally expressed in terms of wavelength, radians or degrees. Forexample, electrical length may be expressed as a multiple orsub-multiple of the wavelength of an electromagnetic wave or electricalsignal propagating within a transmission medium. The wavelength may beexpressed in radians or in artificial units of angular measure, such asdegrees. The electric length of a transmission medium may be expressedas its physical length multiplied by the ratio of (a) the propagationtime of an electrical or electromagnetic signal through the medium to(b) the propagation time of an electromagnetic wave in free space over adistance equal to the physical length of the medium. The electricallength is in general different from the physical length. By the additionof an appropriate reactive element (capacitive or inductive), theelectrical length may be made significantly shorter or longer than thephysical length.

Various embodiments of the present disclosure provide an energy-deliverydevice with a flexible, fluid-cooled shaft. Embodiments may be suitablefor utilization in open surgical applications. Embodiments may besuitable for utilization with hand-assisted, endoscopic and laparoscopicsurgical procedures. Embodiments may be implemented usingelectromagnetic radiation at microwave frequencies, RF frequencies or atother frequencies. An electrosurgical system including the presentlydisclosed energy-delivery device with a flexible, fluid-cooled shaftdisposed in fluid communication with a coolant supply system via aninflow/outflow junction 51 according to various embodiments is designedand configured to operate at frequencies between about 300 MHz and about10 GHz.

Various embodiments of the presently disclosed energy-delivery devicewith a flexible, fluid-cooled shaft are suitable for microwave or RFablation and for use to pre-coagulate tissue for microwave or RFablation-assisted surgical resection. Although various methods describedhereinbelow are targeted toward microwave ablation and the completedestruction of target tissue, it is to be understood that methods fordirecting electromagnetic radiation may be used with other therapies inwhich the target tissue is partially destroyed or damaged, such as, forexample, to prevent the conduction of electrical impulses within hearttissue. In addition, although the following description describes theuse of a dipole microwave antenna, the teachings of the presentdisclosure may also apply to a monopole, helical, or other suitable typeof microwave antenna or RF electrode.

FIG. 1 shows an electrosurgical system 10 according to an embodiment ofthe present disclosure that includes an energy applicator or probe 100with a flexible, fluid-cooled shaft 110 coupled in fluid communicationwith a coolant supply system 150 via an inflow/outflow junction 51. Anembodiment of an energy applicator, such as the probe 100 of FIG. 1, inaccordance with the present disclosure, is shown in more detail in FIG.3. It is to be understood, however, that other probe embodiments mayalso be used.

Probe 100, which is described in more detail later in this disclosure,generally includes an antenna assembly 12 having a distal radiatingportion (e.g., “R” shown in FIG. 3). As shown in FIG. 1, the probe 100is operably coupled by a flexible, transmission line 15 (also referredto herein as a cable assembly) to a connector 14, which further operablyconnects the probe 100 to an electrosurgical power generating source 28,e.g., a microwave or RF electrosurgical generator. Cable assembly 15 mayinclude a proximal end suitable for connection to the electrosurgicalpower generating source 28. At least a portion of the cable assembly 15(e.g., a length that may potentially transfer heat to a patient's bodyduring a procedure) is disposed within the flexible, fluid-cooled shaft110.

In some embodiments, the probe 100 includes a balun structure (e.g., “B”shown in FIG. 3). Balun structure “B”, which is described in more detaillater in this disclosure, generally includes a balun insulator (e.g.,340 shown in FIG. 3) and a conductive balun sleeve (e.g., 350 shown inFIG. 3) disposed around the outer peripheral surface of the baluninsulator, or portions thereof, and may include a balun short (e.g., 351shown in FIG. 3).

According to various embodiments, the flexible, fluid-cooled shaft 110is configured to circulate coolant fluid “F”, e.g., saline, water orother suitable coolant fluid, to remove heat that may generated alongthe length of the cable assembly 15, or portions thereof, during thedelivery of energy, e.g., RF or microwave energy, to the probe 100. Ascooperatively shown in FIGS. 1 and 2A, the shaft 110 includes a cableassembly 15, an inner tubular member 231 disposed around the cableassembly 15 and defining a lumen or fluid inflow conduit 331therebetween, and an outer tubular member 235 disposed around the innertubular member 231 and defining a lumen or fluid outflow conduit 335therebetween. Outer tubular member 235 and the inner tubular member 231are adapted to circulate coolant fluid “F” therethrough, and may includebaffles, multiple lumens, flow restricting devices, or other structuresthat may redirect, concentrate, or disperse flow depending on theirshape. In some embodiments, the inner tubular member 231 is coaxiallydisposed about the cable assembly 15, and the outer tubular member 235is coaxially disposed about the inner tubular member 231. The size andshape of the inner tubular member 231, the outer tubular member 235, thefluid inflow conduit 331, and fluid outflow conduit 335 may be variedfrom the configuration depicted in FIG. 2A.

In some embodiments, at least a portion of the inner tubular member 231and/or at least a portion of the outer tubular member 235 (e.g., adistal portion) may include an integrated, spiraling metallic wire toadd shape-memory properties to the flexible, fluid-cooled shaft 110,e.g., to aid in placement of the probe 100. In some embodiments, theinner tubular member 231 and/or the outer tubular member 235 mayincrease in stiffness and exhibit increased shape-memory propertiesalong their length distally toward the antenna assembly 12.

Shaft 110 may have a variable length from a proximal end of the antennaassembly 12 to a distal end of inflow/outflow junction 51, e.g., rangingfrom a length of about three feet to about six feet. Shaft 110 may haveany suitable outer diameter “D”. In some embodiments, the shaft 110 mayhave an outer diameter “D” in a range from about 0.030 inches to about0.110 inches. Various components of the shaft 110 may be formed ofsuitable, electrically-conductive materials, e.g., copper, gold, silver,or other conductive metals or metal alloys having similar conductivityvalues. Electrically-conductive materials used to form the cableassembly 15 may be plated with other materials, e.g., other conductivematerials, such as gold or silver, to improve their properties, e.g., toimprove conductivity, decrease energy loss, etc.

Cable assembly 15 may be any suitable, flexible transmission line. Cableassembly 15 may include an inner conductor 220, a dielectric material222 coaxially surrounding the inner conductor 220, and an outerconductor 224 coaxially surrounding the dielectric material 222. Antennaassembly 12 may be formed from a portion of the inner conductor 220 thatextends distal to the shaft 110 into the antenna assembly 12. Dielectricmaterial 222 may be formed from any suitable, flexible, dielectricmaterial, including, but not limited to, polyethylene, polyethyleneterephthalate, polyimide, or polytetrafluoroethylene (PTFE) (e.g.,Teflon®, manufactured by E. I. du Pont de Nemours and Company ofWilmington, Del., United States). Inner conductor 220 and the outerconductor 224 may be formed from any suitable electrically-conductivematerial. In some embodiments, the inner conductor 210 is formed from afirst electrically-conductive material (e.g., stainless steel) and theouter conductor 224 is formed from a second electrically-conductivematerial (e.g., copper). In some embodiments, the outer conductor 224 isformed of one or more layers of braided metallic wires, e.g., to improveflexibility characteristics of the cable assembly 15. Cable assembly 15may be provided with an outer coating or sleeve 226 disposed about theouter conductor 224. Sleeve 226 may be formed of any suitable insulativematerial, and may be may be applied by any suitable method, e.g., heatshrinking, over-molding, coating, spraying dipping, powder coating,baking and/or film deposition.

Electrosurgical power generating source 28 may be any generator suitablefor use with electrosurgical devices, and may be configured to providevarious frequencies of electromagnetic energy. In some embodiments, theelectrosurgical power generating source 28 is configured to providemicrowave energy at an operational frequency from about 300 MHz to about2500 MHz. In other embodiments, the electrosurgical power generatingsource 28 is configured to provide microwave energy at an operationalfrequency from about 300 MHz to about 10 GHz.

Electrosurgical power generating source 28 may include a user interface25 in operable communication with a processor unit (not shown). Theprocessor unit may be any type of computing device, computationalcircuit, or any type of processor or processing circuit capable ofexecuting a series of instructions that are stored in a memory. In anembodiment, a surgeon may input via the user interface 25 a selectedpower output, and the electrosurgical system 10 controls the probe 100to automatically adjust the ablation volume by changing the operatingfrequency of the probe 100, e.g., based on the power level and/or levelof reflected power.

Electrosurgical power generating source 28 may include an actuator 40.Actuator 40 may be any suitable actuator, e.g., a footswitch, ahandswitch, an orally-activated switch (e.g., a bite-activated switchand/or a breath-actuated switch), and the like. Actuator 40 may beoperably coupled to the processor by a cable connection (e.g., 17 shownin FIG. 1) or a wireless connection, e.g., a radiofrequency or infraredlink. Electrosurgical power generating source 28 may include a databaseconfigured to store and retrieve energy applicator data, e.g.,parameters associated with one or energy applicators. In use, theclinician may interact with the user interface 25 to preview operationalcharacteristics of an energy-delivery device, such as, for example,probe 100.

User interface 25 may include a display device 21, e.g., a flat-panelgraphic LCD (liquid crystal display), adapted to visually display one ormore user-interface elements (e.g., 23 and 24 shown in FIG. 1). Displaydevice 21 may include touchscreen capability, e.g., the ability toreceive user input through direct physical interaction with the displaydevice 21, e.g., by contacting the display panel of the display device21 with a stylus or fingertip. A user-interface element (e.g., 23 and/or24 shown in FIG. 1) may have a corresponding active region, such that,by touching the display panel within the active region associated withthe user-interface element, an input associated with the user-interfaceelement is received by the user interface 25. User interface 25 mayinclude one or more controls 22, including without limitation a switch(e.g., pushbutton switch, toggle switch, slide switch) and/or acontinuous actuator (e.g., rotary or linear potentiometer, rotary orlinear encoder.) In an embodiment, a control 22 has a dedicatedfunction, e.g., display contrast, power on/off, and the like. Control 22may also have a function that may vary in accordance with an operationalmode of the electrosurgical system 10. A user-interface element 23 maybe positioned substantially adjacent to a control 22 to indicate thefunction thereof. Control 22 may also include an indicator, such as anilluminated indicator (e.g., a single- or variably-colored LEDindicator).

Electrosurgical system 10 includes an inflow/outflow junction 51 coupledin fluid communication with the coolant supply system 150 via one ormore coolant paths (e.g., 19 and 20 shown in FIG. 1), and coupled influid communication with the probe 100 via the flexible, fluid-cooledshaft 110. Coolant supply system 150 may be adapted to circulate coolantfluid “F” into and out of the inflow/outflow junction 51. Coolant source18 may be any suitable housing containing a reservoir of coolant fluid“F”, and may maintain coolant fluid “F” at a predetermined temperature.For example, the coolant source 18 may include a cooling unit (notshown) capable of cooling the returning coolant fluid “F” from theantenna assembly 12 via the shaft 110.

Coolant fluid “F” may be any suitable fluid that can be used for coolingthe cable assembly 15 and/or cooling or buffering the probe 100, e.g.,deionized water, or other suitable cooling medium. Coolant fluid “F” mayhave dielectric properties and may provide dielectric impedancebuffering for the antenna assembly 12. Coolant fluid “F” composition mayvary depending upon desired cooling rates and the desired tissueimpedance matching properties. Various fluids may be used, e.g., liquidsincluding, but not limited to, water, saline, perfluorocarbon, such asthe commercially available Fluorinert® perfluorocarbon liquid offered byMinnesota Mining and Manufacturing Company (3M), liquidchlorodifluoromethane, etc. In other variations, gases (such as nitrousoxide, nitrogen, carbon dioxide, etc.) may also be utilized as thecooling fluid. In yet another variation, a combination of liquids and/orgases, including, for example, those mentioned above, may be utilized asthe coolant fluid “F”.

Coolant supply system 150 generally includes a first coolant path 19leading from the coolant source 18 to the inflow/outflow junction 51,and a second coolant path 20 leading from the inflow/outflow junction 51to the coolant source 18. In some embodiments, the first coolant path 19includes a fluid-movement device 34 configured to move coolant fluid “F”through the first coolant path 19. The position of the fluid-movementdevice 34, e.g., in relation to the coolant source 18, may be variedfrom the configuration depicted in FIG. 1. Second coolant path 20 mayadditionally, or alternatively, include a fluid-movement device (notshown) configured to move coolant fluid “F” through the second coolantpath 20. Examples of coolant supply system embodiments are disclosed incommonly assigned U.S. patent application Ser. No. 12/566,299 filed onSep. 24, 2009, entitled “OPTICAL DETECTION OF INTERRUPTED FLUID FLOW TOABLATION PROBE”.

FIG. 2A shows an embodiment of the inflow/outflow junction 51 of theelectrosurgical system 10 shown in FIG. 1. Inflow/outflow junction 51 isadapted to be fluidly coupleable with the inner tubular member 231 andthe outer tubular member 235 of the flexible, fluid-cooled shaft 110,and adapted to be connected in fluid communication with the coolantsupply system 150. Inflow/outflow junction 51 may have a variety ofsuitable shapes, e.g., cylindrical, rectangular or the like.

Inflow/outflow junction 51 generally includes a housing 250A having anouter wall 285 and an inner wall 275 defining a plurality of interiorchambers and/or openings or ports therein. In some embodiments, theouter wall 285 and the inner wall 275 cooperatively define a fluid inletchamber 262 and a fluid outlet chamber 263, which are described later inthis disclosure.

Housing 250A generally includes a fluid inlet port 52, a fluid outletport 53, and a cable-entry port 59 all defined therein. Cable-entry port59 includes an opening or passage 57 defined in the outer wall 285configured to receive the cable assembly 15 therethrough. Cable-entryport 59 may include a channel or groove 58 adapted to receive an o-ring211 configured to provide a fluid seal between the housing 250A and thecable assembly 15. In some embodiments, a cable-movement restrictor 215may be affixed to or integrally formed with the housing 250A.Cable-movement restrictor 215 may be adapted to restrict movement of thecable assembly 15 and/or adapted to fixedly or releaseably secure thecable assembly 15 to the housing 250A. Cable-movement restrictor 215 mayinclude any suitable fastening element, e.g., clips, clamps, oradhesive.

Fluid inlet port 52 may be adapted to be connected in fluidcommunication with the first coolant path 19. Fluid outlet port 53 maybe adapted to be connected in fluid communication with the secondcoolant path 20. In some embodiments, the first coolant path 19 includesa coolant supply line 31 leading from the coolant source 18 to the fluidinlet port 52, and the second coolant path 20 includes a coolant returnline 35 leading from the fluid outlet port 53 to the coolant source 18.Fluid inlet port 52 and the fluid outlet port 53 may be disposed at anysuitable location along the outer wall of the housing 205. Fluid inletport 52 and the fluid outlet port 53 may have any suitableconfiguration, including without limitation nipple-type inlet fittings,compression fittings, and recesses, and may include an o-ring typeelastomeric seal.

In an embodiment, the fluid inlet port 52 is configured to define afirst recess 252 in the outer wall 285 of the housing 250A, and thefluid outlet port 53 is configured to define a second recess 253 in theouter wall 285. First recess 252 and the second recess 253 may be of anysuitable shape, e.g., rectangular, cylindrical, etc., and may include agroove adapted to receive an o-ring or other suitable sealing element.In some embodiments, the coolant supply line 31 is sealably connectedwith and extends into the first recess 252, and the coolant return line35 is sealably connected with and extends into the second recess 253.

Housing 250A may be adapted to allow a portion of the presentlydisclosed flexible, fluid-cooled shaft 110 (e.g., a portion of the innertubular member 231 and the cable assembly 15) to extend through thefluid outlet chamber 263 and/or the fluid inlet chamber 262. Fluidoutlet chamber 263 is disposed in fluid communication with the fluidoutlet port 53, and may be configured to be coupleable with the outertubular member 235 of the shaft 110. Fluid outlet chamber 263 generallyfluidly connects the fluid outlet port 53 to the fluid outflow conduit335. In an embodiment, the outer wall 285 of the housing 250A isconfigured to define an opening 280 in the fluid outlet chamber 263 toallow the fluid outlet chamber 263 to be connectable in fluidcommunication with the fluid outflow conduit 335.

Fluid inlet chamber 262 is disposed in fluid communication with thefluid inlet port 52, and may be configured to be coupleable with theinner tubular member 231 of the shaft 110. Fluid inlet chamber 262generally fluidly connects the fluid inlet port 52 to the fluid inflowconduit 331. In an embodiment, the inner wall 275 of the housing 250A isconfigured to define an opening 270 in the fluid inlet chamber 262 toallow the inlet chamber 262 to be connectable in fluid communicationwith the fluid inflow conduit 331. The shape and size of the fluidoutlet chamber 263 and the fluid inlet chamber 262 may be varied fromthe configuration depicted in FIG. 2A.

Housing 250A may be configured to be sealingly engageable with the innertubular member 231, e.g., to fluidly connect the fluid inlet chamber 262and the fluid inflow conduit 331, and/or sealingly engageable with outertubular member 235, e.g., to fluidly connect the fluid outlet chamber263 and the fluid outflow conduit 335. Opening 270 defined in the innerwall 275 may be configured to receive the inner tubular member 231.Inner wall 275 may include an engagement portion 276 configured toengage an outer surface of the inner tubular member 231. Sealingengagement between the engagement portion 276 and the outer surface ofthe inner tubular member 231 may be provided, for example, by a sealingelement, e.g., an o-ring, associated with the engagement portion 276.Sealing engagement may be provided by way of threads, external orinternal, disposed on or within the inner tubular member 231 and threadsdisposed within or on the engagement portion 276. It is to beunderstood, however, that sealing engagement between the engagementportion 276 and the outer surface of the inner tubular member 231 may beprovided by any suitable sealing means.

Opening 280 defined in the outer wall 285 may be configured to receivethe outer tubular member 235. Outer wall 285 may include an engagementportion 286 configured to engage an outer surface of the outer tubularmember 235. Sealing engagement between the engagement portion 286 andthe outer surface of the outer tubular member 235 may be provided, forexample, by a sealing element, e.g., an o-ring, associated with theengagement portion 286 of the outer wall 285. Sealing engagement may beprovided by way of threads, external or internal, disposed on or withinthe outer tubular member 235 and threads disposed within or on theengagement portion 286. It is to be understood, however, that sealingengagement between the engagement portion 286 and the outer surface ofthe outer tubular member 235 may be provided by any suitable sealingmeans.

FIG. 2B shows an inflow/outflow junction 151 in accordance with thepresent disclosure. Inflow/outflow junction 151 includes a housing 250Bthat is similar to the housing 250A shown in FIG. 2A except for theconfiguration of the engagement portion 277 of the inner wall 275 andthe configuration of the engagement portion 287 of the outer wall 285.

Engagement portion 277 is adapted to engage the outer surface of theinner tubular member 231 (e.g., similar to the engagement portion 276shown in FIG. 2A). Engagement portion 277 includes a protrusionextending outwardly from the inner wall 275 adapted to engage an endportion of the inner tubular member 231. Inner tubular member 231 andthe engagement portion 277 may be sealingly connected in any suitablefashion, e.g., by a heat-resistant adhesive material, or other suitablesealing material.

Engagement portion 287 is adapted to engage the outer surface of theouter tubular member 235 (e.g., similar to the engagement portion 286shown in FIG. 2A). Engagement portion 287 includes a protrusionextending outwardly from the outer wall 285 adapted to engage an endportion of the outer tubular member 235. Outer tubular member 235 andthe engagement portion 287 may be sealingly connected with aheat-resistant adhesive material, or other suitable sealing material.

FIG. 2C shows an inflow/outflow junction 251 in accordance with thepresent disclosure. Inflow/outflow junction 251 includes a housing 250Cthat is similar to the housing 250A shown in FIG. 2A except for theconfiguration of the engagement portion 278 of the inner wall 275 andthe configuration of the engagement portion 288 of the outer wall 285.

Engagement portion 278 is adapted to engage the outer surface of theinner tubular member 231 (e.g., similar to the engagement portion 276shown in FIG. 2A). Engagement portion 278 includes a generally L-shapedbracket 279 coupled to the inner wall 275 adapted to engage an endportion and the inner surface of the inner tubular member 231.

Engagement portion 288 is adapted to engage the outer surface of theouter tubular member 235 (e.g., similar to the engagement portion 286shown in FIG. 2A). Engagement portion 288 includes a generally L-shapedbracket 289 coupled to the outer wall 285 adapted to engage an endportion and the inner surface of the outer tubular member 235.

FIG. 3 shows an embodiment of the probe 100 of the electrosurgicalsystem 10 shown in FIG. 1. Probe 100 generally includes an antennaassembly 12 having a distal radiating portion “R” disposed within achamber 338 (also referred to herein as a coolant chamber) defined by anend-cap assembly 360. Antenna assembly 12, which is described in moredetail later in this disclosure, includes a proximal arm 370 and adistal arm 380.

End-cap assembly 360 includes a connector portion 368 and an end cap 364disposed at the distal end of the connector portion 368 and coupledthereto. End cap 364 generally defines an interior chamber 365 therein.Connector portion 368 includes a substantially tubular, body member 361defining an interior lumen disposed in fluid communication with theinterior chamber 365 of the end cap 364. Connector portion 368 includesa distal portion 363, e.g., adapted for connection to the end cap 364,and a proximal portion 362, e.g., adapted for connection to the outertubular member 235 of the shaft 110. The shape and size of the distalportion 363 and the proximal portion 362 of the connector portion 368may be varied from the configuration depicted in FIG. 3.

Connector portion 368 may be formed of any suitable material. In someembodiments, the connector portion 368 may be formed of a compositematerial having low electrical conductivity, e.g., glass-reinforcedpolymers or ceramics. Outer tubular member 235 and the proximal portion362 of the connector portion 368 may be sealingly connected with aheat-resistant adhesive material 302, or other suitable sealingmaterial.

End cap 364 includes a tapered portion 320, which may terminate in asharp tip 323 to allow for insertion into tissue with minimalresistance. Tapered portion 320 may include other shapes, such as, forexample, a tip 323 that is rounded, flat, square, hexagonal, orcylindroconical. End cap 364 may be formed of a material having a highdielectric constant, and may be a trocar, e.g., a zirconia ceramic. Insome embodiments, an interior chamber 365 defined by the end cap 364includes a proximal chamber portion 366 and a distal chamber portion 367fluidly coupled to the proximal chamber portion 366. The shape and sizeof the proximal chamber portion 366 and the distal chamber portion 367may be varied from the configuration depicted in FIG. 3.

Probe 100 may be provided with a removable, protective cap 390configured to cover at least a portion of the end-cap assembly 360. Insome embodiments, the protective cap 390 is configured to cover the endcap 364. Protective cap 390 may be removeably disposed over the end cap364 during deployment of the probe 100, e.g., to avoid injuring tissue.Protective cap 390 may be formed of any suitable material, e.g.,plastic, by any suitable process.

Connector portion 368 may be adapted for releasable connection to theprotective cap 390. In some embodiments, the distal end of the connectorportion 368 and the proximal end of the protective cap 390 arereleasably connectable by a screw-fitted connection. In an embodiment,the distal end of the connector portion 368 is provided with a series ofexternal threads 369 configured to matingly engage with a series ofinternal treads 393 disposed at the proximal end of the protective cap390. It will be appreciated that the proximal end of the protective cap390 may be provided with external threads and the connector portion 368may be provided with internal treads. It is to be understood that theprotective cap 390 may be releasably connectable to the connectorportion 368 in any suitable fashion.

Antenna assembly 12 includes a proximal arm 370 and a distal arm 380.Proximal arm 370 may have any suitable length “L2”, and the distal arm380 may have any suitable length “L3”. In some embodiments, the proximalarm 370 may have a length “L2” in a range from about 0.05 inches toabout 0.50 inches. In some embodiments, the distal arm 380 may have alength “L3” in a range from about 0.05 inches to about 0.50 inches.

Proximal arm 370 and the distal arm 380 may be formed of any suitableelectrically-conductive material, e.g., metal such as stainless steel,aluminum, titanium, copper, or the like. In some embodiments, theproximal arm 370 is constructed from a piece of stainless steel, and maybe coated in a high electrical conductivity, corrosion-resistant metal,e.g., silver, or the like. The proximal end 371 of the proximal arm 370is electrically coupled to the distal end 325 of the outer conductor224, e.g., by solder or other suitable electrical connection. In someembodiments, the proximal end 371 of the proximal arm 370 is coaxiallydisposed about the distal end 325 of the outer conductor 224. Proximalarm 370 generally defines a first chamber or cavity 372 thereinlongitudinally extending from the distal end 325 of the outer conductor224. A dielectric material 310 may be disposed within the first cavity372.

Distal arm 380 includes a proximal portion 381 and a distal portion 383.The distal portion 383 of the distal arm 380 is at least partiallydisposed within a cavity defined by the end cap 364. Distal arm 380 hasa stepped configuration, such that the outer diameter of the distalportion 383 is less than the outer diameter of the proximal portion 381.In some embodiments, the proximal chamber portion 366 of the interiorchamber 365 defined by the end cap 364 may be configured to receive theproximal portion 381 of the distal arm 380 therein, and the distalchamber portion 367 of the interior chamber 365 defined by the end cap364 may be configured to receive the distal portion 383 of the distalarm 380 therein. Proximal chamber portion 366 and/or the distal chamberportion 367 may be adapted to allow coolant fluid (e.g., “F” shown inFIG. 1) to circulate around the proximal portion 381 and/or the distalportion 383.

In some embodiments, the distal arm 380 is constructed from a machinedpiece of stainless steel, and may be coated in a high electricalconductivity, corrosion-resistant metal, e.g., silver, or the like. Theproximal portion 381 of the distal arm 380 defines a second chamber orcavity 382 therein. Dielectric material 310 may be disposed within thesecond cavity 382. The distal portion 383 of the distal arm 380 definesa third chamber or cavity 384 therein. Inner conductor 220 extends atleast partially therethrough. Inner conductor 220 may be electricallycoupled to the distal portion 383 by solder 307. In some embodiments,the distal portion 383 of the distal arm 380 includes one or more solderholes 389 defined therethrough.

Distal arm 380 and the proximal arm 370 align at a junction member 311(which is generally made of a dielectric material 310) and are alsosupported by the inner conductor 220 that extends at least partiallythrough the distal radiating portion “R”. Junction member 311 may beformed of low-loss plastic or any suitable elastomeric or ceramicdielectric material by any suitable process. In some embodiments, thejunction member 311 is formed by over-molding and includes athermoplastic elastomer, such as, for example, polyether block amide(e.g., Pebax®, manufactured by The Arkema Group of Colombes, France),polyetherimide (e.g., Ultem® and/or Extern®, manufactured by SABICInnovative Plastics of Saudi Arabia) and/or polyimide-based polymer(e.g., Vespel®, manufactured by E. I. du Pont de Nemours and Company ofWilmington, Del., United States). Distal arm 380 and the proximal arm370 may be insert molded with the junction member 311, such that thedistal arm 380 and the proximal arm 370 are rigidly joined and spacedapart by the junction member 311, defining a feed gap “G” therebetween.In some embodiments, the feed gap “G” may be from about 1 mm to about 3mm.

Probe 100 may include a balun structure “B” having a suitable length“L1”. Balun structure “B” is disposed proximal to and spaced apart asuitable length from the antenna assembly 12. In some embodiments, thebalun structure “B” may be a quarter-wavelength, ¼ λ, sleeve balun, or a¾ λ sleeve balun. Odd harmonics (e.g., ¼ λ, ¾ λ, etc.) may cause acurrent null at the balun entrance, which may maintain a desiredradiation pattern.

Balun structure “B” includes a balun insulator 340 disposed about theouter conductor 224 of the cable assembly 15, and anelectrically-conductive layer 350 (also referred to herein as aconductive balun sleeve) disposed about the balun insulator 340, orportions thereof. A portion 345 of the balun insulator 340 may extenddistally beyond the distal end 355 of the electrically-conductive member350, e.g., to enhance microwave performance of the probe 100 and/orprovide a desired ablation pattern. Conductive balun sleeve 350 may beformed as a single structure and electrically coupled to the outerconductor 224, e.g., by solder or other suitable electrical connection.In some embodiments, the proximal end 352 of the conductive balun sleeve350 may be adapted to allow for connection, e.g., electrically andmechanically, to the outer conductor 224.

Balun structure “B”, according to the embodiment shown in FIG. 3,includes a balun short 351 disposed at the proximal end of the baluninsulator 340. Balun short 351 may be formed of any suitableelectrically-conductive materials, e.g., copper, gold, silver or otherconductive metals or metal alloys. In some embodiments, the balun short351 has a generally ring-like or truncated tubular shape. Balun short351 is electrically coupled to the outer conductor 224 of the feedlineor cable assembly 15 by any suitable manner of electrical connection,e.g., soldering, welding, or laser welding. Balun short 351 iselectrically coupled to the balun outer conductor 350 by any suitablemanner of electrical connection.

Balun insulator 340 may be formed of any suitable insulative material,including, but not limited to, ceramics, water, mica, polyethylene,polyethylene terephthalate, polyimide, polytetrafluoroethylene (PTFE)(e.g., Teflon®, manufactured by E. I. du Pont de Nemours and Company ofWilmington, Del., United States), glass, metal oxides or other suitableinsulator, and may be formed in any suitable manner. Balun insulator 340may be grown, deposited or formed by any other suitable technique. Insome embodiments, the balun insulator 340 is formed from a material witha dielectric constant in the range of about 1.7 to about 10.

Electrically-conductive layer 350 may be formed of any suitableelectrically-conductive material, e.g., metal such as stainless steel,titanium, copper, etc., and may be formed in any suitable manner. Insome embodiments, the electrically-conductive layer 350 has a length ofabout 0.1 inches to about 3.0 inches. The shape and size of theconductive balun sleeve 350 and balun insulator 340 may be varied fromthe configuration depicted in FIG. 3.

Probe 100 generally includes a coolant chamber 338 defined about theantenna assembly 12. Coolant chamber 338 is adapted to circulate coolantfluid (e.g., “F” shown in FIG. 1) around the antenna assembly 12 (asgenerally indicated by the arrows in FIG. 3) and disposed in fluidcommunication with the fluid inflow conduit 331 and the fluid outflowconduit 335. In some embodiments, the coolant chamber 338 is defined bythe end-cap assembly 360 and includes an interior lumen defined by thesubstantially tubular, body member 361 of the connector portion 368.Coolant chamber 338 may additionally, or alternatively, include aninterior chamber 365 defined by the end cap 364. The shape and size ofthe coolant chamber 338 may be varied from the configuration depicted inFIG. 3.

During microwave ablation, e.g., using the electrosurgical system 10,the probe 100 is inserted into or placed adjacent to tissue andmicrowave energy is supplied thereto. Ultrasound or computed tomography(CT) guidance may be used to accurately guide the probe 100 into thearea of tissue to be treated. Probe 100 may be placed percutaneously orsurgically, e.g., using conventional surgical techniques by surgicalstaff. A clinician may pre-determine the length of time that microwaveenergy is to be applied. Application duration may depend on many factorssuch as tumor size and location and whether the tumor was a secondary orprimary cancer. The duration of microwave energy application using theprobe 100 may depend on the progress of the heat distribution within thetissue area that is to be destroyed and/or the surrounding tissue.Treatment of certain tumors may involve probe repositioning during theablation procedure, such as where the tumor is larger than the probe orhas a shape that does not correspond with available probe geometry orradiation pattern.

In operation, microwave energy having a wavelength, lambda (k), istransmitted through the antenna assembly 12, e.g., along the proximalarm 370 and the distal arm 380, and radiated into the surroundingmedium, e.g., tissue. The length of the antenna for efficient radiationmay be dependent on the effective wavelength, λ_(eff), which isdependent upon the dielectric properties of the treated medium. Antennaassembly 12 through which microwave energy is transmitted at awavelength, k, may have differing effective wavelengths, λ_(eff),depending upon the surrounding medium, e.g., liver tissue, as opposed tobreast tissue.

FIG. 4 shows an inflow/outflow junction 451 adapted to be connected influid communication with a portion of a flexible, extendable/retractablefluid-cooled shaft 410 according to an embodiment of the presentdisclosure. Inflow/outflow junction 451 includes a housing 450configured to be releaseably and sealably coupleable with the cableassembly 15 shown in FIG. 1. Housing 450 includes a fluid inlet port452, a fluid outlet port 453, a fluid inlet chamber 462, a fluid outletchamber 463, a tubular sleeve member 489, and a releasable,cable-movement restrictor 415.

Releasable, cable-movement restrictor 415 includes a sealing element411, e.g., an o-ring, and a rotatable member 416. In some embodiments,rotation of the rotatable member 416 in a first direction (e.g., aclockwise direction) effects a compression force on the sealing element415 to restrict movement of the cable assembly 15 and to provide a fluidseal. In some embodiments, rotation of the rotatable member 416 in asecond direction (e.g., a counter-clockwise direction) releases thecompression force on the sealing element 411 to allow movement of thecable assembly 15, thereby allowing extension and/or retraction of theouter tubular member 445 and the inner tubular member 441 of the shaft410.

Tubular sleeve member 489 of the presently disclosed housing 450 isgenerally configured to house a portion of the expandable/retractableshaft 410, and may have any suitable length “L4”. Fluid inlet port 452,fluid outlet port 453, fluid inlet chamber 462, and fluid outlet chamber463 shown in FIG. 4 are similar to the fluid inlet port 52, fluid outletport 53, fluid inlet chamber 262, and fluid outlet chamber 263 shown inFIG. 1, respectively, and further description thereof is omitted in theinterests of brevity.

Flexible, extendable/retractable fluid-cooled shaft 410 is adapted toallow for selective adjustment of the length of the fluid-cooled shaft410. In some embodiments, the shaft 410 may be selectively adjustable toany length between a first length (e.g., “L5” shown in FIG. 5), when theshaft 410 is in its most retracted use configuration, and a secondlength (e.g., “L6” shown in FIG. 5) when the shaft 410 is in its mostextended use configuration. Flexible, extendable/retractablefluid-cooled shaft 410 generally includes an inlet sleeve 431, an outletsleeve 435, an inner tubular member 441 coaxially disposed about andslideably coupled to the inlet sleeve 431, and an outer tubular member445 coaxially disposed about and slideably coupled to the outlet sleeve435. In some embodiments, a first lubricous sleeve 408 may be disposedbetween the inner tubular member 441 and the inlet sleeve 431, and asecond lubricous sleeve 409 may be disposed between the outer tubularmember 445 and the outlet sleeve 435.

First lubricous sleeve 408 and the second lubricous sleeve 409 may beformed of any suitable non-conductive insulator, e.g., a TEFLON® sleeve.First lubricous sleeve 408 and/or the second lubricous sleeve 409 may beselected based on materials properties, e.g., density and lubricity, toallow for sliding of the inner tubular member 441 over the inlet sleeve431 and/or sliding of the outer tubular member 445 over outlet sleeve435. First lubricous sleeve 408 and/or the second lubricous sleeve 409may additionally, or alternatively, be selected to prevent damage and/orminimize wear to the inner tubular member 441 and/or the outer tubularmember 445. First lubricous sleeve 408 and/or the second lubricoussleeve 409 may be formed of a lubricous polymeric material, such as ahigh-density polyolefin (e.g., polyethylene), polytetrafluoroethylene(a.k.a. PTFE or TEFLON®, manufactured by E. I. du Pont de Nemours andCompany of Wilmington, Del., United States), or polyurethane. Firstlubricous sleeve 408 and/or the second lubricous sleeve 409 may beformed by heat-shrinkage, extrusion, molding, dip coating, or othersuitable process. In some embodiments, the insulator sleeve 270 mayinclude a surface coating formed of highly hydrophilic, low-frictionpolymer, such as polyvinylpyrrolidone, polyethyleneoxide,polyhydroxyethylmethacrylate, or copolymers thereof.

In some embodiments, the shaft 410 may be configured in its mostretracted use configuration when the proximal end of the inner tubularmember 441 is disposed proximally in substantial alignment with theproximal end of the inlet sleeve 431 and/or the proximal end of theouter tubular member 445 is disposed proximally in substantial alignmentwith the proximal end of the outlet sleeve 435.

FIG. 5 shows the flexible, extendable/retractable fluid-cooled shaft 410and the inflow/outflow junction 451 of FIG. 4 in its most retracted useconfiguration in accordance with an embodiment of the presentdisclosure. In its most retracted use configuration, the fluid-cooledshaft 410 may have any suitable length “L5”. In some embodiments, theflexible, extendable/retractable fluid-cooled shaft 410 may be providedwith one or more shape-retention elements 510 adapted to provideresistance to change in the outer diameter of the shaft 410, e.g.,during expansion/retraction of the shaft 410 and/or during thecirculation of coolant fluid therethrough. Shape-retention elements 510may be disposed around the outer tubular member 445 and/or slideablycoupled to the outer tubular member 445.

FIG. 6 shows the flexible, extendable/retractable fluid-cooled shaft 410and the inflow/outflow junction 451 of FIG. 4 in its most extended useconfiguration in accordance with an embodiment of the presentdisclosure. In its most retracted use configuration, the fluid-cooledshaft 410 may have any suitable length “L6”.

The presently disclosed energy-delivery devices with a flexible,fluid-cooled shaft are capable of directing energy into tissue, and maybe suitable for use in a variety of procedures and operations. Theabove-described energy-delivery device embodiments may be suitable forutilization with hand-assisted, endoscopic and laparoscopic surgicalprocedures. The above-described energy-delivery device embodiments maybe suitable for utilization in open surgical applications.

Various embodiments of the presently disclosed energy-delivery devicewith a flexible, fluid-cooled shaft may allow the surgeon to deploy anablation probe, e.g., between closely spaced boundaries of tissuestructures, to reach the location of the ablation site. Theabove-described energy-delivery device embodiments may allow the surgeonto manually deploy an ablation probe having a flexible, fluid-cooledshaft with his/her hand to place the probe at difficult-to-reachlocations, such as, for example, the dome of the liver near the top ofthe diaphragm. Various embodiments of the presently disclosedenergy-delivery devices with a flexible, fluid-cooled shaft including alength of cable assembly surrounded by inner and outer tubular membersadapted to circulate coolant fluid therethrough may lessen thepotentially unwanted heat transfer from the cable assembly to thepatient's body during a procedure, e.g., an ablation procedure.

The above-described inflow/outflow junction embodiments are adapted tobe coupled in fluid communication with the inner and outer tubularmembers of the above-described flexible, fluid-cooled shaft embodiments,and adapted to be coupled in fluid communication with a suitable coolantsupply system. The presently disclosed inflow/outflow junctionsembodiments may be adapted to be coupled in fluid communication with acoolant supply system and adapted to selectively allow movement of acable assembly therethrough, e.g., to facilitate theextension/retraction of an extendable/retractable fluid-cooled shaft.

Electrosurgical systems including an energy-delivery device with aflexible, fluid-cooled shaft according to embodiments of the presentdisclosure may be fluidly coupled to a coolant supply system via theabove-described inflow/outflow junction embodiments.

Although embodiments have been described in detail with reference to theaccompanying drawings for the purpose of illustration and description,it is to be understood that the inventive processes and apparatus arenot to be construed as limited thereby. It will be apparent to those ofordinary skill in the art that various modifications to the foregoingembodiments may be made without departing from the scope of thedisclosure.

1-17. (canceled)
 18. A fluid flow junction operably coupled to a firsttubular member defining a first fluid conduit and a second tubularmember disposed around the first tubular member and defining a secondfluid conduit therebetween, the fluid flow junction comprising: ahousing configured to be in fluid communication with a coolant supplysystem, the housing including an outer wall and an inner wall; a firstfluid chamber defined by the outer and inner walls, the inner walldefining an opening in the first fluid chamber to fluidly couple thefirst fluid chamber to the first fluid conduit; a second fluid chamberdefined by the outer and inner walls, the outer wall defining an openingin the second fluid chamber to fluidly couple the second fluid chamberto the second fluid conduit; a cable assembly disposed within at leastone of the first fluid conduit or the second fluid conduit; and amovement restrictor operably coupled to at least one of the cableassembly or the housing, the movement restrictor configured to impart acompression force on the cable assembly upon movement of the movementrestrictor to a first position wherein movement of the cable assemblythrough the movement restrictor is restricted and to release thecompression force on the cable assembly upon movement of the movementrestrictor to a second position wherein movement of the cable assemblythrough the movement restrictor is enabled, the movement restrictorincluding a rotatable member configured to rotate in a first directionabout an axis transverse to a longitudinal axis of the fluid flowjunction to move the movement restrictor toward the first position andin a second direction about the axis transverse to the longitudinal axisto move the movement restrictor toward the second position.
 19. Thefluid flow junction of claim 17, wherein a diameter of the opening inthe first fluid chamber is smaller than a diameter of the opening in thesecond fluid chamber.
 20. The fluid flow junction of claim 17, whereinthe cable assembly includes an inner conductor and an outer conductorcoaxially disposed about the inner conductor and separated by adielectric.
 21. The fluid flow junction of claim 17, wherein themovement restrictor includes a sealing element disposed around the cableassembly.
 22. The fluid flow junction of claim 17, further comprising acable-entry port defined by an outer surface of the housing, thecable-entry port configured to allow passage of the cable assemblytherethrough.
 23. The fluid flow junction of claim 17, furthercomprising a fluid inlet port defined in the outer wall and in fluidcommunication with the first fluid chamber.
 24. The fluid flow junctionof claim 17, further comprising a fluid outlet port defined in the outerwall and in fluid communication with the second fluid chamber.
 25. Thefluid flow junction of claim 17, wherein the housing is further adaptedto be sealingly engageable with the first tubular member.
 26. The fluidflow junction of claim 17, wherein the outer wall includes a firstengagement portion configured to engage an outer surface of the secondtubular member.
 27. The fluid flow junction of claim 26, wherein thefirst engagement portion includes a protrusion extending outwardly fromthe outer wall adapted to engage a proximal portion of the first tubularmember.
 28. The fluid flow junction of claim 26, wherein the firstengagement portion includes a generally L-shaped bracket coupled to theouter wall adapted to engage a proximal portion and an inner surface ofthe first tubular member.
 29. The fluid flow junction of claim 17,wherein the housing is further adapted to be sealingly engageable withthe second tubular member.
 30. The fluid flow junction of claim 17,wherein the inner wall includes a second engagement portion configuredto engage an outer surface of the first tubular member.
 31. The fluidflow junction of claim 30, wherein the second engagement portionincludes a protrusion extending outwardly from the inner wall adapted toengage a proximal portion of the second tubular member.
 32. The fluidflow junction of claim 30, wherein the second engagement portion and thesecond tubular member are sealingly connected by a heat-resistantadhesive.
 33. The fluid flow junction of claim 30, wherein the secondengagement portion includes a generally L-shaped bracket coupled to theinner wall adapted to engage a proximal portion and an inner surface ofthe second tubular member.
 34. The fluid flow junction of claim 17,wherein the housing is configured to threadingly couple to the firsttubular member.
 35. The fluid flow junction of claim 17, wherein themovement restrictor is further configured to restrict movement of thecable assembly relative to the housing.